Self-dispensing dental floss applicator

ABSTRACT

A self-dispensing dental floss applicator has a U-shaped elongated housing with two hollow prongs set perpendicularly to the body at one end and a larger opposite end to contain a locking mechanism, a dispensing mechanism, a spool of fresh floss and a spool of used floss.

FIELD OF THE INVENTION

The present invention relates to tooth flossing and, more specifically, to a self-dispensing dental floss applicator usable for inserting a string or ribbon of dental floss between two single teeth and cleaning the gap between these teeth by repeatedly moving the floss back and forth and up and down.

BACKGROUND OF THE INVENTION

Dentists recognise dental flossing as a necessary and effective part of teeth cleaning and plaque removing. Flossing is indeed the only effective method for cleaning between the teeth to remove plaque build-up, which is the primary cause of gingivitis, periodontal and tooth decay. For good results, flossing should be performed daily. Beside the related applications of the applicant, today there is not any practical, well-designed device that gives consumers a high level of satisfaction with regard to usage, hygiene, etc. Finger flossing continues to be the most common method used by people even though it is primitive and does not provide good results especially for the rear teeth.

A dental floss applicator is known from EP 0 661 026 B1. According to EP 0 661 026 B1 a self-dispensing dental floss applicator is known revealing a generally U-shaped housing, having a space for a spool of floss at its one end and two hollow prongs extending parallel to each other at its other end, the floss being spanned between the free ends of the prongs and passed from the spool through a locking mechanism, a guiding section, the hollow prongs back to the guiding section and the locking mechanism wherein the locking mechanism consists of a casing, rotatably mounting a lever with double eccentric acting on two grip pads and a grip pad spring provided between said grip pads and said casing. The self-dispensing dental floss applicator known from the prior art needs the power of the fingers of the user to move the floss and is therefore less comfortable and moves the floss very slowly. Furthermore the used floss has to be cut by the user and therefore the applicator known from the prior art is less hygienic in use.

SUMMARY OF THE INVENTION

It is an object of the invention to create a self-dispensing dental floss applicator mitigating the disadvantages of the prior art and being easy to handle and less expensive in production.

The above mentioned problems will be solved by a self-dispensing dental floss applicator with a generally u-shaped housing having a space for a spool of floss at its one end and two hollow prongs at its other end, the floss being spanned between the free ends of the two prongs and passed from the spool through a locking mechanism, a guiding section, the hollow prongs back through the guiding section and the locking section, wherein the housing contains a second spool and that the first spool contains the fresh floss and that the second spool is for accumulating the used floss, wherein the second spool contains a gear wheel to drivingly connecting the gear wheel with a drive unit.

According to the invention it is advantageous that the gear wheel meshes a rack with gear teeth slidingly accommodated in a cavity of the housing.

Furthermore, it is helpful that the rack is in connection with a shaft, which can be easily operated with a lever.

According to another embodiment of the invention it is of advantage that the rack is biased by a spring, such that the spring exercises a longitudinal force along its axis pushing the rack forward. The spring is preferably a spiral spring or another type of spring.

Furthermore, it is of advantage that the shaft and the rack are connected by another spring-type element or spring element.

According to another embodiment of the invention, it is of advantage that the housing of the applicator contains an opening in the rear end of the housing allowing a driving gear wheel to be at least partly introduced through the opening to mesh the gear wheel within the housing.

Furthermore, it is of advantage that the driving gear wheel is part of a base element. According to another embodiment it is of advantage that the base element contains an electric motor, at least one battery and a switching element to start or stop the electric motor. Instead of a battery another power supply means may be provided too.

According to another inventive embodiment, it is helpful that the switching element is a micro switch being easily operated by introducing the rear end of the applicator in a recess of the base.

Furthermore, it is of advantage that the base comprises a guiding element like a positioning groove which is in operational connection with an element of the housing of the applicator.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the invention will be apparent from the following description of an exemplary embodiment of the invention with reference to the accompanying drawings, in which:

FIG. 1 shows different views of an inventive floss dispensing applicator;

FIG. 2 shows different sectional views of the inventive applicator; and

FIG. 3 shows details of the inventive applicator;

FIG. 4 shows details of an embodiment of the inventive applicator; and

FIG. 5 shows details of an embodiment of an inventive applicator.

FIG. 6 shows details of the locking mechanism of the inventive self-dispensing dental floss applicator.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 and FIG. 2 both show different views of an inventive floss dispensing applicator. The applicator consists of a housing 1, which is preferably u-shaped and made of plastic material. The housing 1 allows performing flossing in the most practical and user friendly way and especially with easy reach of the rear molar teeth. At the rear end of the housing there is a spool 3 arranged to provide fresh floss. This spool 3 may be removed and exchanged if the fresh floss is fully used and therefore the fresh floss spool is empty. The spool 3 is located in a section of the housing which is covered by the cap 2. The cap 2 protects and holds the spool 3 in position.

At the front end of the housing 1 there are two hollow prongs 4 a, 4 b arranged to provide a predetermined floss tension for flossing. The floss is fed through the prongs and kept under tension. Especially the floss is fed from the spool 3 through one of the prongs 4 a, 4 b to the second prong 4 b, 4 a to a used floss spool.

In the prongs are borings 13 a, 13 b located to maintain floss in position and to keep the tension of the floss while the floss is feed through the borings 13 a, 13 b. The prongs are arranged in an angle of about 90° or less and the borings 13 a, 13 b are arranged accordingly in an angle relative to each other.

Within the housing there is a locking casing 5 which houses a locking mechanism of the made of a lever 6 an axle and grip pads 7, 17 and springs 8. The core elements are quickly removed by pulling them out of the housing 1 in vertical direction.

The lever 6 is designed as a double eccentric lever to provide locking and tension of the floss. Additionally the lever 6 is a dispensing actor in a mechanical version of the applicator. As can be seen in FIG. 1, the lever 6 is located at least partly in the housing 1 and consists of a part not located in the housing.

The grip pads 7, 17 are divided in lower grip pads 17 a, 17 b and upper grip pads 7 a, 7 b. The both types of grip pads are designed to exercise pressure on floss under rotation of lever 6 and action of spring 8. The grip pads are made of metal or of plastic material. The grip pads 7, 17 both contain saw teeth pattern.

The spring 8 is made of metal or of e.g. plastic material and is located below the lower grip pads. The spring 8 is made as curved strip spring.

The lever axle 9 is preferably made of metal or plastic material and keeps the lever 6 in a defined position and allows the lever 6 to turn around the axle 9.

FIG. 1 shows the guiding partition in the view from below situated at the top of FIG. 1. Similarly they can be seen on FIG. 2. FIG. 4 shows additionally guiding partitions 10 inside the housing 1 which can be provided in the housing of FIGS. 1 or 2 too, but they are not seen. The guiding partitions are used to guide the floss from the fresh floss spool to the bores 13 or from the bores 13 to the used floss spool. Reference sign 11 denotes a bore to guide fresh floss from the locking mechanism to the bore 13 a, while reference sign 12 denotes a bore to guide used floss from the bore 13 to the used floss spool or to locking mechanism. As can be seen in FIG. 4, the bores 11 and 12 are almost parallel and they are located between the lever 6 mechanism and the prongs 4.

In FIG. 4 the fresh floss 15 is shown while the used floss 16 is shown too. Both the fresh and the used floss are almost parallel within the housing 1 and the fresh floss 15 is spanned between the prongs 4 a, 4 b to allow the flossing. The used floss is floss already used which will be reeled on a used floss spool 18 or 21.

The used floss spool 18 is located in the housing 1 and covered by the cap 14 which protects and holds the spool and gear within the housing 1. The spool 18 contains he used floss which is reeled and the spool contains a large gear, which goes in rotary motion when the floss is dispensed in the electrical version of the applicator.

As can be seen in FIG. 4, the applicator may contain an additional tension pin 19 and an adjustable screw 20 to increase the floss tension and to provide additional floss tension.

FIG. 2 shows the used floss spool 21 with a small gear wheel which is going into rotary motion when the floss is dispensed. Additionally to the spool with the small gear wheel the applicator contains a mechanism to drive the gear wheel 21. This mechanism contains a shaft 22 which transmits a linear movement of the shaft into a rotational movement of the gear wheel 21. The shaft is therefore provided with gear teeth in linear arrangement as can be seen as rack 23. In case the shaft is moved linear the gear wheel 21 is turned around the axis of the gear wheel. As can be seen the shaft 22 transmits movement of the rotating lever 6 to the rack 23. The rack is part of the rack-and-pinion-gear device to transmit a linear movement into a rotational movement. Since the rack is moving against the force of the spring 24, the spring 24 is able to actuate the rack 23 accordingly.

The spring 24 is realised as cylindrical spring but can be realised as other type of spring if necessary. The spring provides a required pressure on rack 23 to push the rack back in starting position when the lever 6 is rotated forward to lock the floss between the grip pads 7, 17.

When the lever 6 is rotated backward the floss will be dispensed and when the lever is rotated forward the floss dispensing mechanism will be stopped.

According to FIG. 2 the housing 1 contains a dispensing mechanism casing 25, which is the rear part of the housing 1 of the applicator. The casing 25 houses the shaft 22 the rack 23 and the spring 24. Therefore, the casing can be designed as having a longitudinal hollow bore containing the above mentioned parts 22 to 24. According to another embodiment of the invention, the casing can be installed in a cavity of the housing 1 of the applicator, preferably before the spool 21 is installed in the housing 1 and maintained in position by cover 14.

According to FIG. 2, the shaft 22 and the rack 23 are movable relative to each other. They both elements 22 and 23 have a sliding surface with which both elements can slide relatively to each other. A spring 26 is provided between shaft 22 and rack 23 to allow shaft 22 to remain in position in the casing 25 while the rack is free to slide. The spring may have a second function such that the spring 26 pushes the rack back in the upper position such that the rack frees itself from the teeth of the gearwheel 18 when going back in its resting position, what can be seen in FIG. 3.

The embodiment of the FIGS. 4 and 5 is provided with an electrical base 27. The base 27 is preferably a molded plastic part including a recess for the reception of the applicator or of at least the rear end of the applicator. The base comprises an element to allow a stable positioning of the base, i.e. a socket.

As can be seen in FIG. 4, the applicator can be positioned such that the rear end of the housing 1 is accommodated within the base 27. Within the housing there is an opening such that a gear wheel 33 can protrude through this opening to mesh the gear wheel 18 of the applicator. The gear wheel 33 is part of the base 27.

According to FIG. 5, the base 27 includes a base cover 28 which closes the bottom of the almost semi-spherical base 27. The base cover is almost flat and allows a tight closure of the base. Preferably the closure is watertight. The cover is preferably made of plastic material. The fixation of the base cover 28 can be done using three screws or with other fastening means.

Within the base is an electrical motor 29 provided. Preferably the electric motor 29 is a low voltage DC-motor, e.g. a 1.5 V DC-motor. At the drive shaft of the motor 29 is a gear wheel provided which meshes an other gear wheel in driving connection. This double gear wheel can be seen in FIG. 5 and is denoted by reference sign 33. The double gear wheel allows the driving connection between the electric motor and the gear wheel 18. The electric motor is connected via electrical leads with a power supply, e.g. with batteries. As power supply two batteries 30 a, 30 b are shown which are e.g. alkaline batteries of the disposable type or accordingly batteries of the rechargeable type. The batteries 30 a, 30 b may be of 1.5 V type. According to FIG. 5 the batteries 30 a, 30 b are parallel aligned and are positioned above each other. According to FIG. 5, the batteries are disposed in a battery storage room which is closed by a battery cover 31, which can be of the clip-on type. This cover 31 protects and holds the batteries in their cavity inside the base 27. To operate the electric motor a micro switch 32 is provided to switch the electric motor on or off. Preferably the micro switch 32 will be activated when the applicator is inserted in the cavity of the base and is pressed downward in the direction of the base. Accordingly the micro switch is adjusted to receive the rear part of the applicator when the applicator is inserted in the cavity of the base and switches the electric motor on.

Within the base is at least one holding part 34 or a holding strap which holds the elements 29, 32 and 33 in place. This holding element can be a molded part of plastic material. The holding part or strap is fastened with fastening means, e.g. fastening screws 35. According to the shown embodiment five screws are used to fasten and hold the strap 34 in position inside the base 27.

Furthermore, fastening means 36 are used to hold the base cover 28 in position and to fasten the base cover. According to the shown embodiment of FIG. 5 three screws are used as fastening means 36.

Additionally, as can be seen in FIG. 5, a positioning groove 37 is provided in the base which co-operates with a positioning element of the applicator to allow the applicator to be placed properly within the base during a dispensing action.

Additionally, as can be seen in FIG. 3, an anti-return device 38 is provided which prevents spool 18 and/or 21 to rotate back after it has been in rotary motion to reel used floss on wheel and hence dispensed new fresh floss between the prongs. Therefore, the anti-return device is a flexible element with a teeth portion which co-operates with a teethed portion of a wheel 18 and/or 21 to allow only a rotation in one direction of the wheel.

According to the invention, the applicator allows a floss locking mechanism. The presence of two curved strip springs 8 a, 8 b placed underneath the lower gripping pads 17 a, 17 b ensures that the pressure exercised by the gripping pads 7, 17 on the floss is almost constant independent of the floss characteristics or floss materials e.g. Nylon or Teflon, string or ribbon, waxed or non-waxed and thickness tolerances are.

Furthermore, a thin partition in the casing 5 of the locking mechanism between the fresh floss and used floss ensures that no direct contact exists between the two paths for fresh and used floss. Therefore there is no direct contact between fresh floss and used floss in any part of the applicator making it extremely hygienic. Furthermore, floss spools, both fresh 3 and used floss 18 or 21 are located in two separate closed compartments of the applicator. There is no direct contact with any part of the human body (mouth or hand). The fact that used floss is isolated in a confined environment is a positive factor.

After each use of the applicator, the user is asked to wash the frontal part of the applicator, i.e. the prongs and the spanned floss under the tap before a new part of floss is dispensed between the prongs. This practice means used floss is relatively clean before being stored in its spool.

According to an inventive embodiment, a change in tightness of floss is possible. Should the user wants to obtain a tighter floss beyond what the mechanism already provides, he just needs to unscrew the little screw 20 which will receive downward pressure from the lever 6 when this one is in final locked position. As such, extra pressure will be exercised on the used floss string 16 from pin 19 as it passes through it.

The introduction of the dual function of the lever in the mechanical version of the self-dispensing dental floss applicator is generally favourable. The mechanical version of the inventive self-dispensing dental floss applicator according to FIGS. 1 to 3 relies on finger power to obtain floss dispensing. It is a lower cost and slower version of the electrical model described according to FIGS. 4 and 5 yet it performs the same function. The double eccentric lever 6 continues to play a floss locking role.

For ease of use, the action to lock the floss is by pressing forward lever 6 with the thumb and unlock by pulling it backward with the index finger. When the lever 6 reaches almost 45 degrees forward, the fresh floss is locked between the gripping pads 7 a and 17 a while the used floss will be locked completely between the gripping pads 7 b, 17 b as the lever 6 is pressed down completely. The added feature of the extra tension pin 19 allows creating more tension on the floss if/when required by the user.

The lever plays also the added role of floss dispenser. By pulling the lever 6 backward with the index finger, a shaft 22 in the sliding mechanism is moved backward and the rack-and-pinion gear system 23 and 21 generates a rotary motion of the used floss spool 21. Hence, the used floss 16 is pulled away from the prongs 4 a and 4 b at the end of the applicator. The user just needs to action the lever backward a few times to get a new part of fresh floss to be spanned between the prongs of the applicator. The lever is brought back to its neutral position thanks to spring 24 and spring/pin 26 in the sliding mechanism. It has to be noted that spring strength of spring 24 is far stronger than spring 26. Device 26 allows shaft 22 to slide away from rack 23 which in turn moves up and disengages itself from the teeth of gearwheel 21 before reaching its resting position The used floss spool 21 can only rotate in one direction as a small blocking mechanism 38 prevents it from unreeling.

FIGS. 4 and 5 show a fully electrical self-dispensing floss applicator to provide ultimate user-friendliness and easy dispensing of floss. The inventive applicator is a combination of a light ergonomic applicator and a stable compact electrical base. In order to fully control the movement of floss between teeth and avoid hurting gums, it is critical that the applicator be as light, user-friendly and ergonomic as possible.

The incorporation of an electrical motor, a gear box and a set of batteries in the applicator itself would create a heavy, unbalanced and bulky applicator. Such characteristics would make it very difficult and almost impractical for the user to floss safely and effectively.

The electrically driven applicator of FIGS. 4 and 5 has essentially a similar design as the mechanical version described above according to FIGS. 1 to 3. The main difference is that lever 6 needs only to perform the locking function and, as such the sliding dispensing mechanism is not needed. The used floss reel 18 incorporates a large gearwheel that allows it to be set in rotary motion from outside the casing.

FIG. 6 shows details of the locking mechanism of the inventive dental floss applicator in different sectional views. Sectional view mm shows the lever 6 in an open position, perpendicular to the housing 1, where both fresh floss 15 and used floss 16 are free to move such that floss dispensing is performed. The free movement of the floss is possible since the both elements 7 a, 17 a including the saw-teeth have a certain distance such that the floss is free to move.

Sectional view nn and sectional view oo show the lever in a 45 degree position where fresh floss 15 is locked (sectional view nn), while the used floss 16 is being tensioned (sectional view oo) by the dispensing mechanism.

Sectional view p and sectional view rr show the lever 6 in the final locked position, alligned with housing 1. The sections pp and rr show fresh floss 15 and used floss 16 totally locked under pressure exercised by lever 6 on grid pads 7 a and 7 b and by springs 8a and 8 b on grip pads 17 a and 17 b respectively.

A compact base 27 contains the electrical motor, the gearbox and the set of two e.g. AA batteries. By holding vertically and pressing down the unlocked applicator in the cavity located at the top of the base 27, a small micro switch 32 activates the electrical motor, which in turn sets the double gearwheel 33 in rotary motion. A positioning groove 37 that receives shape 38 ensures the applicator is placed properly on the base. The used floss spool 18 in the applicator is set in rotary motion and the flossed is dispensed rapidly. The user just needs to press the lever 6 forward in locked position while the floss is dispensed electrically by the base. The key feature here is the speed and ease at which dispensing of floss is made. Here again, the extra tautness feature 19 exists according to one inventive embodiment. The applicator is ready for use.

One of the great advantages of such design is that a family does not need as many electrical bases as they need applicators. One base per bathroom is enough as it can be used by many applicators. Additionally, 1.5 Volt AA batteries can be of a disposable or rechargeable nature. The base is compact enough to accompany the user during trips away from home. The base also plays the role of applicator stand when not in use.

The invention relates to a self-dispensing dental floss applicator that has a U-shaped elongated housing 1 with two hollow prongs 4 a, 4 b set perpendicularly to the body at one end and a larger opposite end to contain the locking mechanism, the dispensing mechanism, the spool 3 of fresh floss and the spool 18 and/or 21 of used floss. The locking mechanism composed of a casing 5, an axle 9, two lower grip pads 17 a, 17 b, two upper grip pads 7 a, 7 b, two strip springs 8 a, 8 b and a lever 6 with two eccentric friction parts is used to hold the floss in position thus creating the right tension on the floss. According to an embodiment of the invention, a tension pin 19 containing a screw 20 is provided to increase floss tension if/when needed by the user. Rotating the lever 6 up unlocks the floss. Further repeated rotations of the lever backward action the sliding mechanism containing a rack-and-pinion gear 23, 21, together with springs 24, 26, that in turn causes the spool of used floss 21 to rotate. Hence, new fresh floss is spanned between the prongs. In a separate embodiment, the applicator is placed on the electrical base and pressing it down will cause the spool of used floss 18 to rotate, hence pulling new fresh floss between the prongs in a very fast and easy manner. Pushing back the lever 6 to its locked position ensures the floss is tightly locked with the right tension.

REFERENCES

-   1 housing -   2 cap -   3 spool -   4 prong -   5 casing -   6 lever -   7 grip pad -   8 spring -   9 axle -   10 guiding partition -   11 bore -   12 bore -   13 bore -   14 cap -   15 fresh floss -   16 used floss -   17 grip pad -   18 spool -   19 pin -   20 screw -   21 spool -   22 shaft -   23 rack -   24 spring -   25 casing -   26 spring -   27 base -   28 base cover -   29 electrical motor -   30 battery -   31 battery cover -   32 switch -   33 gear wheel -   34 holding part -   35 screw -   36 fastening means -   37 positioning groove -   38 anti-return device 

1. Self-dispensing dental floss applicator comprising: a generally u-shaped housing 1 having a space for a spool 3 of floss at its one end and two hollow prongs 4 a, 4 b at its other end, the floss being spanned between the free ends of the two prongs 4 a, 4 b and passed from the spool through a locking mechanism, a guiding section 10, the hollow prongs 4 a, 4 b back through the guiding section 10 and the locking section, wherein the housing 1 contains a second spool 18, 21 and that the first spool 3 contains the fresh floss and that the second spool 18, 21 is for accumulating the used floss, wherein the second spool 18, 21 contains a gear wheel to drivingly connecting the gear wheel with a drive unit.
 2. Self-dispensing dental floss applicator according to claim 1, wherein the gear wheel meshes a rack with gear teeth slidingly accommodated in a cavity of the housing.
 3. Self-dispensing dental floss applicator according to claim 2, wherein the rack 23 is in connection with a shaft 22, which can easily operated with a lever
 6. 4. Self-dispensing dental floss applicator according to claim 2, wherein the rack 23 is biased by a spring 24 such that the spring exercises a longitudinal force along its axis pushing the rack 23 forward.
 5. Self-dispensing dental floss applicator according to claim 2, wherein the shaft and the rack are connected by a spring element.
 6. Self-dispensing dental floss applicator according to claim 1, wherein the housing contains an opening in the rear end of the housing allowing a driving gear wheel to be introduced through the opening to mesh the gear wheel within the housing.
 7. Self-dispensing dental floss applicator according to claim 1, wherein the driving gear wheel is part of a base element.
 8. Self-dispensing dental floss applicator according to claim 7, wherein the base element contains an electric motor, at least one battery and a switching element 32 to start or stop the electric motor.
 9. Self-dispensing dental floss applicator according to claim 8, wherein the switching element is a micro switch to be operated by introducing the rear end of the applicator in a recess of the base.
 10. Self-dispensing dental floss applicator according to claim 8, wherein the base comprises a guiding element like a positioning groove which is in operational connection with an element 38 of the housing 1 of the applicator.
 11. Self-dispensing dental floss applicator according to claim 1, characterised in that a tighter floss is achievable by unscrewing the screw 20 located in a pin 19 which will receive downward pressure from the lever 6 when it is in a final locked position, therefore an extra pressure will be exercised on the used floss string 16 from pin 19 as it passes through it.
 12. Self-dispensing dental floss applicator according to claim 1, characterised in that a locking mechanism 5, 6, 7 a, 7 b, 8 a, 8 b, 9, 17 a, 17 b is provided such that the locking mechanism consists of a casing 5 rotatably mounting a double eccentric lever 6 acting on two grip pads 7 a, 7 b and locking the floss on the two grip pads 17 a, 17 b under upward pressure of at lest one spring 8 a, 8 b.
 13. Self-dispensing dental floss applicator according to claim 1, characterised in that the floss spools of fresh and used floss are located in two separate compartments located in the housing 1 closed by covers 2,
 14. 14. Self-dispensing dental floss applicator according to claim 13, characterised in that the floss spools are not in direct contact with any part of the human body while the self-dispensing floss applicator is in normal use for flossing. 